


The Thing That Couldn't Leave

by InkMango the Fabulous (CesiAmber)



Category: Undertale (Video Game)
Genre: Blood and Gore, Demon Summoning, Demonic Possession, Dont read later on if you get squeamish easily, Horrific Imagery, Human Sans, Implied/Referenced Alcohol Abuse/Alcoholism, Kidnapping, More tags to be added, Transformation, demonic au, jacksepticeye cameos, sassy narrator, some swears
Language: English
Status: In-Progress
Published: 2016-08-29
Updated: 2016-08-29
Packaged: 2018-08-11 18:14:53
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,503
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7902766
Author URL: https://archiveofourown.org/users/CesiAmber/pseuds/InkMango%20the%20Fabulous
Summary: <blockquote class="userstuff">
              <p>Sometimes it's hard to just get by when you have a vendetta and a plan. Even the best plans go ary, after all. And sometimes, you can't help but get in too deep and let it get personal, even when it literally kills you to let someone dangerous get too close.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> So I finally rewrote this and I plan to make this a doozy. Chapter 2 might take a while tho, so be patient with me please.

"HELP US!"

A child's wail permeated the air, trying to stop the bleeding of the other child.

"Somebody!"

Cruel, empty eyes glared down at them in a jawless face as a floating cyan heart shape sat clenched in bone shard hands.

"P-please…"

Flashing red and blue lights drew the attention of the demon to outside the circle, away from the vulnerable children beneath the incomplete bone monster. The being quickly swallowed the soul before the DIU could capture and take the soul from him. The partially dislodged door was kicked down, the demon captured, and the children, one sobbing, one growing cold to the touch and crumbling slowly before the elder brother's eyes, sent to the hospital.

—

The young boy stood by the block of granite implanted into the ground, staring at the plot of upturned grass at its foot. It wasn't raining, despite the gloom that pervaded the very stalks of grass that shuddered from the gentle breathing of the air. A name was carved deep into the polished stone memorial, a name the boy knew all too well. "It should have been me…" whimpered the child, one that knew deep down that there was no possible way to possibly avoid this outcome.

The funeral had been a closed-casket ceremony; the boy knew first hand that the oak box with fine birch engravings had been empty, a waste of money. He stared at the stone monument, etching each detail into his mind. His parents let him help design the tombstone, a way to help the boy cope. He chose the coolest font he could find for the coolest brother a person could have. He absentmindedly scratched at the rough white bandages protecting the stitches in his arm and the cracked ribs in his chest, wishing for some way for his brother to come back.

A pair of good, black eyes tore away from the monolith and looked up at the only other mourners left, his parents. His petite mother sobbed into her husband's side while he stared somberly into the distance with misted eyes. After a few moments of watching them, the boy stumbled over to the heartbroken couple, hugging his mother around the waist; his father was startled out if his stupor when his mother choked on her own breath briefly. "Let's go home" offered the tall man after several beats of silence within the embrace, whom of which scooped up the child and led the family back to their vehicle. They drove off, leaving the sleeping bones around them to their comas as the boy kept his eyes locked on the newest addition to the lonely lot.

A wind pulled itself away from the breeze to watch the boy intently, sensing the whim and doing its best to make it come true. It would take some time though.

—

A loud, abrasive buzzing filled the once-dead room. A messy, dark brunette head poked its way out of the wrinkled, crumpled covers with a deep-throated groan of annoyance. How he despised that noise. He fumbled for the alarm so he could get a few more moments of peace. Finding the small plastic mesa he quested for, he clicked it neatly into the provided depression and attempted to return to sleep. The glowing blue numbers announced just how much day had been wasted this way. Between the nightmares about the accident and his work, he had barely any time to rest anymore since he moved to the college dorms. That spelled bad news as he was sometimes late to his morning classes and his thoughts would drift in class. It didn't help that he was naturally a little scatterbrained and tended to forget his homework altogether.

With a suffering sigh, the young adult heaved himself out of bed with the intention of being on time for once. He may be exhausted, but he wasn't going to waste his money on a demonology degree he didn't get because he was lazy. That, and he had nothing better to do since he couldn't return to sleep for the moment thanks to that stupid alarm his mother got him about five years ago.

The shower water was too hot this morning, probably because he made the mistake of using the toilet beforehand. His unruly chocolate locks fought against the teeth of his comb, a battle he eventually left for dead when the cheap plastic tines snapped and almost lodged themselves in its enemy. He held a bundle of faded, sooty red cloth close to his chest and inhaled the long-faded scent, trying to remember its owner in life preambling disaster and cursing a name he would never know. The door never got locked. He never had anything to steal and he'd misplaced the keys in his first month there. "Hey." he simply greeted the student across the hall. She'd always ignored him since she was usually listening to music in some form. Today, however, she waved back warmly to him as she knocked on the door for her roommate to let her in.

There was no elevator today, so he took the stairs down to the ground floor. Someone had spilled some form of red paint on the floor, leaving a huge splatter stain and streaks that looked almost like blurred out runes as the janitors tried to clean up the mess. The bottoms of his shoes were stained when he'd had to walk through it. He wrinkled his nose at the acrid stench of cheap acrylic.

One could follow the red shoe prints on the concrete to the science building of the college. The person that left them behind would be too much in a hurry to care, since the mess in the dorm lobby had held him up for a while, even if he'd woken up early for once. He'd managed to slide into a seat in the lecture hall just in time for roll call.

"Samson Fontenot?"

He'd indicated his presence when he'd heard his name. The class carried on without any preamble.

—

The milkshake vacuumed up the straw with a snrrrrrrrrk, a pair of intent hazel eyes trained on the student across from them. Said student was tan-skinned, though the tan was paler than usual due to the student's current health issues and lack of sleep; his unruly curly hair was the color of dark, rich chocolate, and his eyes matched from between heavy eyelids. "Samson?" The name made its owner jolt awake, eyes wide and meeting the hazel ones present. The pale face said eyes were housed in blinked, a pair of blond eyebrows sloping in worry. "Are you sure you want to keep going with the interview? You've zoned out at least three times now…" the journalist inquired of the man across from her, tucking a wispy lock of dirty blonde behind her ear. He merely shrugged her off with a half-hearted grin. "I haven't been sleeping well, lately." he admitted. She nodded in understanding. "Yeah, I know how it is." she winced sympathetically at the other student's predicament. "Anyways, back to the task at hand…"

Samson stiffened when the journalist dug into her bag and brought out a manilla envelope stamped with [TOP SECRET] in the most cliche way possible. The envelope was slid across the diner booth table and shaking hands gingerly caressed the sealed corner, short and bitten nails slightly scratching at the flap. "Don't tell anyone about this, okay Sam? Both of us could get in serious trouble if people find out that you're trying to summon a demon, no matter your intentions. It's even worse for you, with your weird, vengeful obsession." Samson pursed his lips and simply gave the journalist a determined nod, locking eyes with her. "I'll have to look into the demon's name for the summoning." she continued, and the student across from her sent her a sobered look. "Thanks for doing this, Jules. I know it's risky of you to be doing this."

"Don't get used to it." Jules scoffed, taking another sip from her previously abandoned milkshake. Sam chuckled, deep and rumbling like distant thunder. The college student sidled out out of his seat, dusting salt off of his black basketball shorts from the fries he'd dined on earlier and tucked the envelope under his arm. He placed a few dollar bills on the table and silently waved goodbye to Jules as he walked out with a warm grin on his face. He paused at the edge of the sidewalk and stared up at the cloudy blue sky. He took a deep breath, knowing that his little brother used to love days like this.

He turned sharply, face darkening, and stalked briskly down the street in the direction of the shadier section of town. He nonchalantly flipped up the hood on his sweater and stuffed his free hand into his pocket as he tramped down the street, the buildings getting steadily shabbier and more broken. His pacing slowed near an old, long-abandoned car garage, dusty and marred with decades of accumulated graffiti, rust, and elemental wear. There was a busted stop sign with the paint flecked off and painted over in deep maroon. The symbol was a bleeding heart stabbed through the middle with a black, warped dagger. If he was honest with himself, he didn't trust this cult as far he could throw its heaviest member, especially since this was the cult that had helped kill his baby brother, but this was the best shot he'd get at avenging poor little Paris.

A pair of bright, almost inhuman eyes stared at him in the darkness behind his back. "Hello?" he called into the dim lighting of the garage, the faint and faded lines of a circle painted in red contrasting sharply with the oil, scorched concrete. "I have a proposition." he offered, holding the envelope in front of him, turning and darting his eyes in search of someone. "A proposition, you say?" a voice of indeterminable gender asked. The door slammed shut behind him as a haunting chuckle resonated in the room. "How interesting." "You should never have come here." the voice whispered before something covered his mouth and nose, making everything go hazy, his eyes rolling back into his skull.

—

Everything around him was an orange haze. His bleary, drugged vision cleared enough to identify the five candles set in a circle, smoky cinnamon incense making him sneeze and screw up his face; the particles of smoke suspended in the air were left glowing orange in the firelight. A looming shadow squatted next to the bound college student, the opened manilla folder in one of the hands. "You plan to summon a demon, do you not?" the figure asked, standing straight and beginning to pace next to Sam's face. "You came to the right people." he could hear the smirk in the cloaked person's voice, the sharp rasp of pages turning interrupting the languid crackling of the candles. "Unfortunately, there is a…"

There was a glint of bloodstained metal for a brief moment.

"... price for our services."

A door behind him opened, and more cloaked cultists marched dutifully into the room as the leader of the group sheafed through the file. They eventually closed the folder and pulled out a knife, polishing it on their cloak sleeve with tender precision. An ominous chanting began between the ring of followers, the red painted lines seeming to absorb the minimal light coming from the candles. The cult member with the file smirked tauntingly as they stepped forward with the glistening knife, causing Sam to try scooting away from them, only to notice that he'd been tied up. "The demon you want us to summon is rather specific…" the cult leader bemoaned, caressing the sharp edge of the knife. "I'm afraid that your price to have us summon this demon for you will be higher than usual."

He scooted himself farther into the circle, away from the menacing blade that his eyes didn't stray from once since his eyes first met it. The lovingly polished silver swung down, about to strike him in the neck, when a bright light burst in the room, blinding everyone. Squinting through the light, Sam was barely able to make out a form piecing itself together, parts materializing out of thin air. A loud clacking filled the room as the being landed in the center of the circle, dangerously close to landing on the delicate neck of the human below him. Sam was frozen in shock, staring at the… thing that had just appeared out of thin air.

A long skull with thin eyes, high, prominent cheekbones, and a squared jaw stared down at him, brow line bent into a concerned expression. It then looked up at the cultists, clearly confused. "IS THIS HUMAN ALRIGHT?" it boomed, its eldrich voice making the walls of the room vibrate from the sheer volume of it. A clump of ceiling plaster bounced off of Sam's forehead. He began to feel lightheaded and dizzy from the revelation that there was a demon standing over him, in the perfect position to kill him and take his soul, and the demon was asking about his state of being. "HUMAN? YOU ARE TRULY WORRYING ME!"

The cultmaster cleared their throat, catching the attention of the bone creature. A pristine white skull turned to the cloaked being, warily eyeing the blade in their hand. "We humbly offer this sacrifice in favor of your services." they offered, bowing slightly in a show of respect. The skeleton frowned in distaste, parking it's segmented hands on its pelvis. "I DO NOT THINK YOU UNDERSTAND WHAT IS HAPPENING HERE." the demon glowered, the candles puttering out one by one until ithe room was pitch black. There was some scuffling before something knocked into Sam's head, knocking him out.


	2. Waking Up AKA The Most Original Chapter Title Ever

**Summary for the Chapter:**

> In which, as the chapter title clearly states, Sam wakes up to a way too friendly demon. Also, interruptions everywhere!

**Notes for the Chapter:**

> Yes, ik it's been like 8 months since i first posted, but i can explain
> 
> Shimeji  
> Wander Over Yonder  
> Pheonix Wright  
> Homeschool
> 
> that is all

Sam awoke to being uncomfortably warm with bleary vision and his hair sticking to his sweaty, sticky forehead. His mouth felt like sandpaper, the distinct taste of dried saliva making him wish for a glass of water. He sat up, vision swimming, on the couch in his dorm. How —?!

He cradled his throbbing head in his hand, some sort of red crust flaking off his temple as he pondered what had happened… yesterday? The day before? He has no clue how long he'd been out, though survey suggests that it had been a good few hours at the least. He groaned in derision, digging the heels of his palms into his eye sockets as if that could grind away the headache piercing his train of thought. At least that explained the red crust…

He stretched as he stood up, feeling a slight grey ache one gets from being in the same position for too long. He yawned a bit despite having just woken up from a rather long forced nap.

“AH, HUMAN!”

Sam shrieked, whipping his attention to the skeleton grinning rather brightly from the doorway leading to the kitchen as he took a rather comical defensive pose. 

“YOU'RE FINALLY AWAKE! AND THE RED STUFF STOPPED LEAKING FROM YOUR HEAD!”

Sam instinctively put a hand to his temple and looked at the rusty red dust that had rubbed off on it again. He looked back to the grinning skull with suspicion. Skeleton demons were the most violent and confrontational demons out there, Sam knew from experience. “How did we get to my dorm? Moreover, unseen by anyone?” he asked the skeleton, whom of which looked worried and began sweating bullets, disappearing back into the kitchen. “OH, WE DEMONS HAVE THESE THINGS CALLED SHORTCUTS! YOU HUMANS WOULD CALL IT TELEPORTATION!”

Of course he could teleport, he was an Eldrich, otherworldly being. He guessed that he should count himself lucky that the voice the demon was using currently sounded more human than he would care to admit rather than the echoey, layered shit that had been used at the summoning . Sam ran his hand over his face, leaving streaks of rust scented crimson dust as his headache pounded on like the drum in a death metal or screamo song. He felt like he should provide some vocals. He remembered a portion of what the weird cultist had said: the demon he'd tried to summon was very specific. This demon that had taken him home bore a close resemblance to the demon that had taken Paris, as he recalled. But he acted way too much like his brother had before the… incident, nothing at all like a demon. Could he be —

“HUMAN, THE FOOD IS READY!”

Sam was getting tired of his thoughts being interrupted. “What did you make?”

“YOU HUMANS WOULD CALL IT SPAGHETTI AS I RECALL.”

Sam had a minor wheat allergy. He didn't even own any spaghetti noodles. Why must he suffer so? He trudged out to the kitchen, dreading the meal, and he sat in one of the cheap dining chairs that looked way too similar to one of those uncomfortable chairs in a high school classroom.

The plate he was presented was thankfully one of the paper plates instead of one of the porcelain ones, which meant fewer dishes to wash. What was on the plate, however… no sugarcoating it, it was gelatinous mush with vague suggestions of noodles covered in mashed tomatoes. Sam felt his face instinctively scrunch up at the scent of over boiled noodles; he tried his best to hide his gagging from the eagerly watching demon when he choked down a bite, his still-dry mouth making it even harder to swallow the strange substance. It's no Soylent Green at least, although in this particular situation he almost would prefer it if it were. “It’s, uh…” he could practically see the skeleton’s eye sockets light up in anticipation. With a quick cough, Sam desperately tried to change the subject with a sense of bewilderment about how bizarre this situation was becoming.

“Say, I don't think we've introduced ourselves! I'm Sams-”

“IT'S A PLEASURE TO MEET YOU, SANS!”

“My name isn't Sans-”

“I AM THE GREAT PAPYRUS!”

“Great, but my name still isn’t-”

“IT IS NOT OFTEN THAT HUMANS SHARE NAMING CONVENTIONS WITH DEMONS.”

“Normally they don't, like how my-”

“YOU MUST TRULY BE A NOBLE HUMAN, SANS!”

“... Yeah, sure, let's go with that.” Sam finally relented, glad that Papyrus had at least taken the bait and switched topic. However, with the topic switched so suddenly, Sam was at a loss about what to say. He mentally floundered for a new conversational subject when Papyrus clacked some of his bones together without warning.

“I HAVE HEARD MANY... THINGS ABOUT HUMANS, AND I WISH TO KNOW IF THEY ARE TRUE OR NOT!” Papyrus hesitantly began with clear intent for a Q&A session. “Sure, ask away.” Sam flatly responded, crossing his arms and legs as he gave Papyrus a mildly interested look to hide how much he was mulling over the situation. Papyrus seemed a little nervous, little beads of magic sweat beginning to roll down his domed ivory forehead.

A sharp ringing interrupted just as Papyrus opened his mouth… teeth? No, mouth, he was positive. Then again... Sam halted that train of thought and held up a finger in a clear gesture of “one moment please” to answer his cell. There have been way too many interruptions today, it was unbelievable; it was almost like a bad fanfiction with no other way to progress the plot was using the same thing over and over to try and be creative.

“Sam, where have you BEEN?!” a loud, accented voice demanded, causing Sam to wince at the audio blast to the ear, the image of his green-haired friend coming to mind instantly. “Everyone's been asking where you are, you almost never miss class even if you were late, but now you're missing days left and right!”

Sam sucked in a breath through his teeth. That answered how long he'd been out. He had confronted the cult on Thursday and hadn't had another class until the next Monday. “Sean, what day is it?” Sam asked tentatively, starting to get worried. “You seriously don't know?” challenged Sean, taking on some incredulity at Sam's query. “I wouldn't be asking if i did” bitterly replied the dark brune. “Dude, it's the anniversary of your brother's death, isn't it? You've been gone for like a week.”

Sam didn't get to hear the last sentence. He was too busy being shell shocked, the phone dropping to the ground and cracking the screen. His lips pursed painfully and his eyes glazed over as his body stiffened. Oh, the irony of it all. Sam's became uncomfortably aware of just how dry his mouth was, his tongue feeling thick and fat as it clung to the sides of his gums to retain what little moisture remained. He tried to focus on anything else, anything but THAT day, anything but Paris, mind scrambling for something to grip onto.

“SANS, ARE YOU ALRIGHT? YOU DIDN'T BREAK LIKE BEFORE, DID YOU?” Papyrus was asking him worriedly, but even his distinct, clear voice sounded like it was coming through staticky, and the words never stuck in his mind, forgotten the moment they were heard. Papyrus, fearful and not knowing what else to do, shakes Sam in an attempt to break him out of his stupor. “SANS, WHY ARE YOUR EYES LEAKING? IS SOMETHING THE MATTER?” Papyrus kept asking, silently begging for an answer. All he got was ragged, short breathing and a trembling human subconsciously trying to curl into himself, the soundtrack of another human’s tinny voice over a phone line asking questions and the faint sound of a jackhammering heart in a cage of bone. Finally succumbing to fear, Papyrus wraps his arms around the human’s quivering form and squeezes tightly but gently, hoping to the König that it would do SOMETHING to help.

Sam almost immediately started calming down, the breathy thrum of magic giving him something to focus on and time his breathing to. Haltingly, his trembling arms rose and wrapped themselves around Papyrus, returning the hug almost painfully. The skeleton only hugged a bit tighter in response, hoping it wouldn't happen again and that he wasn't hurting his new friend. They remained like this for a good while before Sam finally dropped his stradied arms, face buried in wet paper mache armor with a dry snrrk every so often.

“I need a drink.” Sam hoarsely muttered to himself, licking his chapping lips with a rough, bumpy tongue. Papyrus let the human go, and said human got off the crappy chair and grabbed a glass out of the cupboard; he filled it up with water and downed the whole glass in mere seconds, spilling some on his face and having some difficulty swallowing from how closed up his throat has gotten from his crying, which had certainly not helped his dehydration issue. He drank three more glasses of water this way before he started to moderate himself by taking sips and smaller gulps due to how ill he'd started feeling from introducing so much of the liquid to his system at once. 

The human took a moment’s break from drinking all that water to use it to wash the dried blood off his face. He tried his best to look at the blunt force trauma wound in the reflection on the faucet, but he didn't get too good of a look and gave up after a few moments. He opened his fridge, finding a couple beers in one of the crisper drawers he hasn't noticed when he last checked. He grabbed one, asked the demon if he drank to a confused response, and heavily sat down on the chair opposite from where he'd previously seated himself with a huge whoosh of air being let out of his lungs. He popped open the beer with a practiced ease and took a swig of the bitter substance, savoring the taste in his mouth. He swallowed that mouthful as he set the glass bottle down and tipped his head back to lounge as best as he could sprawled out haphazardly on the uncomfortable high school dining chair, taking a deep breath and enjoying the silence in his dorm, mind buzzing and muddling already from the potent drink.

Papyrus in the meantime sat himself in the chair Sam had been seated in, watching the human intently as he hydrated himself way too fast to be particularly healthy. The bone demon mulled over everything his demonic friends had told him about humans, how they relied more on physical sustenance than a demon, and the way Sam was currently drinking the water like it was saving his life added credence to those tellings. The other, brown drink confused him. It smelled strange and clearly had a relaxing effect on the human slumped across from him. “I drink too much.” the human slurred a bit from emotional fatigue, pinching the bridge of his nose and shaking his head as he sat hunched over once again, taking another generous sip of the beverage. “Especially on todays since I was legal to drink.” 

That made more sense in his head, but he digressed. Papyrus wouldn't get it either way.

There was a frantic knocking on the door of the dorm, to which Sam loudly protested with a groan after taking another drink from the bottle.

He stood up and shuffled towards the door, clearly not pleased with the green haired Irishman on the other side. “Jesus, Sam, you’re drinking again?” Sean asked, clearly recognizing the way Sam held himself in that moment. “I thought we cleared it all out last time!”

“Crisper” was the curt response, a clearly drunk Sam swaying a bit on the spot. He dimly wonders with his last shred of common sense if he might be concussed from when he got hit in the head since he never got this delirious whenever he drank himself to sleep.

Sean sighed, steadying Sam by the shoulders and pushing him gently back into the dorm. “I think you need some sleep, buddy, you're acting weirder than you usually do when you drink too much.” the green haired man suggested, unknowingly in agreement. “Normally, you just sit at a table and cry, maybe fall asleep, not give everyone a sleepy death glare.”

Sam was guided gently to his bedroom, and Sean took no notice of the skeleton that had disappeared from the kitchen.

Sam fall asleep almost instantly despite the still logical part telling him that that was a very bad idea, and Sean took the partially empty bottle and the still unopened bottle in the fridge to dispose of later, muttering under his breath about his friend's abhorrent habits and the need to go food shopping. Papyrus in his incorporeal form witnessed the whole thing, ghosting to Sam’s room to check on him. He was sleeping peacefully, which may or may not have been a good sign. Sean left the house with no fanfare, closing the door behind him with a soft click from the latch.


End file.
